Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Consider the following relational schema: Doctor(DName,Reg_no) Patient(Pname, Disease) Assigned_To (Pname,Dname) Give expression in both Tuple calculus and Domain calculus for every of the queries:(i) Get the names of patients who are assigned to more than one doctor. (ii) Get the names of doctors who are treating patients with ‘Polio'.
Ans: (i)Tuple Calculus: {p[PName] | p ∈ PATIENT ∧ ∃a1, a2 (a1 ∈ ASSIGNED_TO ∧ a2 ∈ ASSIGNED_TO ∧p[PName] = a1[PName] ∧ a1[PName] = a2[PName] ∧ a1[DName] ≠ a2[DName])} Domain Calculus:{p | ∃p1, d1, p2, d2 (
∈ PATIENT ∧ ∈ ASSIGNED_TO ∧ ∈ASSIGNED_TO ∧ p1 = p2 ∧ d1 ≠ d2)} (ii)Tuple Calculus: {u[Dname] | u ∈ ASSIGNED_TO ∧ ∃t (t ∈ PATIENT ∧ t[Disease] = ‘Polio' ∧t[PName] = u[PName])} Domain Calculus: {d | ∃p1, p2, s2 ( ∈ ASSIGNED_TO ∧ ∈ PATIENT∧ p1 = p2 ∧ s2 = ‘Polio')}
what do you mean by consistency in rdbms?
#questiononsider the following relation: CAR_SALE =(CAR_ID,oPTION_TYPE, Option_listpreice, Sale_date, Option_discountedprice)..
What are composite attributes? Composite attributes can be separated in to sub parts.
East Coast Aquarium Relational Database
Data Base Management System 1. Draw the Architecture of MySQL and explain about its subsystems briefly. 2. Elaborate with the help of an example the concept of Primary key a
Homework chapter 10 no 3
Why did SAP introduce the extended star schema? Explain why it is reported to be better than the traditional schema model?
Explain Candidate key? Candidate Key - A candidate key is a minimal superkey, that can be used to uniquely identify a tuple in the relation.
Describe identifying relationship? Identifying relationship: It is relationship among strong entity and a weak entity it is represented through a doubly outlined diamond in C
Differance between Unordered and ordered file ? Unordered file do no has any sequence although ordered file has arranged in a few sequence and data are assigned in ordered form
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd